Animal Communication: Introduction and Evolutionary History

1. Animal Communication: Introduction and Evolutionary History ZOL 313 June 3, 2008

2. Animal Communication: Introduction and Evolutionary History • Objectives: • Become familiar with different sensory modes of animal communication and be able to generate hypotheses and predictions. • Understand how sensory exploitation may have influenced the evolution of communication signals in animals. ZOL 313 June 3, 2008

3. Communication: Modes of animal communication: Visual Auditory Tactile Chemical/Olfactory Other (Electric, Sonar, etc.)

4. Visual Communication Hypothesis: Prediction: Signalers: Fruiting plants Receivers: Birds (blackcaps)

5. Visual Communication Example: http://news.bbc.co.uk/2/hi/science/nature/7219803.stm

6. Auditory Communication Who are male birds singing to? Hypothesis 1: Rival repulsion Prediction:

7. Auditory Communication Who are male birds singing to? Hypothesis 2: Mate attraction Prediction 1: Females will respond more strongly Prediction 2: Male song will increase

8. Tactile Communication Example: Social Grooming Functions of social grooming:

9. Chemical/Olfactory Communication Hypothesis: Pheromone: a chemical that triggers a natural behavioral response in another member of the same species Prediction:

10. Chemical/Olfactory Communication Hypothesis: Squirrels rub snake skin scent on themselves Prediction:

11. “Other” Modes of Communication Example: Weakly electric fish

12. Combination of Sensory Modes Example: Spotted hyena greeting behavior Why do female spotted hyenas have a psuedopenis? Costs: Benefits:

13. The Evolution of Communication Alternate wing-waving Slow wing-waving Pre-takeoff Sky-pointing Throwback Cormorants Gannets Boobies Anhingas Rapid wing-waving Both wings waved Wing waving Pre takeoff Example: Rapid-flutter wing-waving Pelicans

14. The Evolution of Communication Example: Whistling moth males How did they evolve ears to hear this signal? Ancestral State: Saturnid moths have mechanoreceptor cells that carry information A whistling moth ancestor may have had mechanoreceptor cells that gave it Whistling moths have similar anatomy but

15. The Evolution of Communication Ancestral signals can be co-opted for a new function. Example: Whistling moth ear probably was first adaptive in detecting Example: Some bowerbirds co-opted an aggressive signal

16. The Evolution of Communication Sensory exploitation: a situation where a signaler is able to tap into a preexisting sensitivity or bias in the perceptual system of a receiver Example: Female “net stance” may have evolved first as predatory behavior (N).

17. The Evolution of Communication Sensory exploitation: a situation where a signaler is able to tap into a preexisting sensitivity or bias in the perceptual system of a receiver Example: Hypothesis: Female guppies originally were attracted to orange spots Prediction: Females with stronger preferences for males with orange spots

18. The Evolution of Communication Sensory preferences can exist in current species that have never encountered a particular signal before. Example: Female X. maculatus fish

19. The Evolution of Communication Sensory preferences can exist in current species that have never encountered a particular signal before. Hypothesis: Prediction:

20. The Evolution of Communication Sensory preferences can exist in current species that have never encountered a particular signal before. Zebra finches do not have crests. Neither do their close relatives 1. Does this experiment support the hypothesis that female zebra finches have a sensory preference for a novel signal? Why/why not? 2. From this experiment, what color feathers (white, red, green, or all three) would you guess female zebra fiches use to line their nests and why?

21. The Evolution of Communication Sensory “exploitation” does not mean responding to the signal is maladaptive for the receiver. For example, female that responded positively to males with an exaggerated signal could have gained fitness for several reasons, such as: 1. 2.